title: Does skeletal surgery for asymmetric mandibular prognathism influence the soft tissue contour and thickness?
abstract: OBJECTIVE
  The purpose of the present study was to investigate whether asymmetric mandibular prognathism accompanies a fundamental difference in soft tissue thickness and whether asymmetric mandibular setback surgery would influence the contour and thickness of the soft tissue of the chin.
  
  
  METHODS
  The present retrospective study included skeletal class III patients with significant mandibular chin deviation greater than 6 mm at the pogonion, who had undergone cone-beam computed tomography before and 6 months after surgery during a 2-year period. The predictor variables were timing (pre- and postoperatively) and side (asymmetric vs contralateral). The outcome measures were the hard and soft tissue contours and soft tissue thickness of the chin at the infradentale, B-point, and pogonion level evaluated with reformatted computed tomography images. The study variables were statistically compared using regression model and correlation analysis.
  
  
  RESULTS
  The present study consisted of 20 patients (10 males and 10 females; average age 20.2 years; range, 18 to 25). Preoperatively, the chin deviation side showed a more prominent hard and soft tissue outline but had a thinner soft tissue thickness, which camouflaged the hard tissue asymmetry. After surgery, the hard and soft tissue outline was greatly improved, and the soft tissue thickness had become nearly symmetric. Most of the soft tissue thickness changes correlated negatively with the hard tissue changes.
  
  
  CONCLUSIONS
  Asymmetric mandibular prognathism accompanied the 3-dimensional soft tissue contour and thickness asymmetry. Because the soft tissue responds favorably after skeletal surgery, the correction of 3-dimensional asymmetry of bone should be emphasized in patients with asymmetric mandibular prognathism.
authors.affiliation: Center for Orthognathic surgery, Department of Oral and Maxillofacial Surgery, Kyungpook National University School of Dentistry, Daegu, Korea.
authors.forename: Sung-Tak
authors.initials: ST
authors.lastname: Lee
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Mori
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Minami
authors.forename: Chang-Hyeon
authors.initials: CH
authors.lastname: An
authors.forename: Jin-Woo
authors.initials: JW
authors.lastname: Park
authors.forename: Tae-Geon
authors.initials: TG
authors.lastname: Kwon
mesh_terms: D000293:Adolescent; D000328:Adult; D002508:Cephalometry / Q000379:methods; D002680:Chin / Q000473:pathology; D054893:Cone-Beam Computed Tomography / Q000379:methods; D004424:Ear Canal / Q000473:pathology; D005145:Face; D005146:Facial Asymmetry / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007180:Incisor / Q000473:pathology; D008297:Male; D008313:Malocclusion, Angle Class III / Q000601:surgery; D008334:Mandible / Q000473:pathology / Q000601:surgery*; D009295:Nasal Bone / Q000473:pathology; D009915:Orbit / Q000473:pathology; D059229:Osteotomy, Sagittal Split Ramus / Q000379:methods; D011378:Prognathism / Q000601:surgery*; D012189:Retrospective Studies; D012658:Sella Turcica / Q000473:pathology; D016896:Treatment Outcome; D055815:Young Adult